Hand Operated Worm GearboxDesigned to suit manual applications, the HOW/MPR worm gear operators are quarter-turn devices intended for the operation of ball, plug and butterfly valves.The HOW/MPR gear operators include low lead angle gearing designed to be inherently self-locking.Torque range from 39,000 Nm (28,765 lbf.ft) to 264,000 Nm (194,716 lbf.ft). 9 sizes. Ratios from 1229:1 to 7171:1.Carefully chosen ratios to meet manual rim effort requirementsProtected steel input shaftRemovable output sleeveDuctile iron gearcaseAngular contact bearings supporting worm shaftRepositionable baseplate facilityOptions include:High and low temperaturesStainless steel input shaftAll types of environmentLimit switchesFixed and flexible extensionsChain wheels